Re: patch for datetime.c

Tom Lane wrote:
>
> Joseph Shraibman <jks@selectacast.net> writes:
> > [root@d1 ~/postgresql-7.1/src/backend/utils/adt] diff -C 3
> > datetime.c.orig datetime.c
> > *** datetime.c.orig     Thu May  3 21:16:37 2001
> > --- datetime.c  Thu May  3 21:19:51 2001
> > ***************
> > *** 2087,2092 ****
> > --- 2087,2096 ----
>
> >         sec = (tm->tm_sec + fsec);
>
> > +       if (sec >= 59.995)
> > +               sec = 59.99; /* Round down to avoid times like
> > 2001-05-03 21:18:60.00-04 */
> > +
> > +
> >         switch (style)
> >         {
> >                         /* compatible with ISO date formats */
>
> This is a horrid solution.

Well not horrid, but stopgap.  There needed to be soemthing that kept
there from being 60 seconds in the output.

>
> The correct solution is to round the original timestamp to two
> fractional digits before it's ever broken down into y/m/d/h/m/s.

I was afraid to modify the timestamp object.  I didn't know what side
affects that might have.  And I wasn't sure how to create a timestamp
from another timestamp.
>
> At least if you only want two digits of precision.  I think Thomas
> has been resisting making that change because he wants to allow
> displaying more than two digits, instead.
>
That was the other thing I considered, but I thought two digits was
there because it was standard.

> BTW, is there really only one routine with this problem?
>
Err, sort of.  There is another method in the same file that operates on
time and appears to have the same bug, but times aren't supposed to have
fractional seconds.

playpen=# select '5:33:59.999'::time;
 ?column?
----------
 05:33:59
(1 row)

So I'm not sure if that other function is a problem or not.

--
Joseph Shraibman
jks@selectacast.net
Increase signal to noise ratio.  http://www.targabot.com